The biosensor for monitoring asparagine levels in Fruit juices was developed in present research work. Lasparaginase (biocomponent) has been extracted from Withania somnifera (L) Dunal, and immobilized into TEOS hydrosol gel-chitosan matrix. Kinetic characterization of both native and immobilized enzyme was compared. Response time studies had been carried out by Phenol Red indicator coimmobiliz...

(15)NH(4) (+) and [(15)N](amide)-glutamine externally supplied to detached nodules from soybean plants (cv. Tamanishiki) were incorporated within nodule tissues by vacuum infiltration and metabolized to various nitrogen compounds during 60 minutes of incubation time. In the case of (15)NH(4) (+) - feeding, the (15)N abundance ratio was highest in the amide nitrogen of glutamine, followed by glu...

After the first isolation of asparagine in 1806 by Vauquelin and Robiquet (l), there were numerous studies of its properties and physiological significance (2-4). Piria (5) in 1848 was probably the first to adduce evidence for a physiological role of asparagine during the life cycle of plants, and also to observe its transformation or metabolism by yeast. However, it was not until approximately...

Asparaginase (EC 3.5.1.1) was isolated from the developing seed of Pisum sativum. The enzyme is dependent upon the presence of K+ for activity, although Na+ and Rb+ may substitute to a lesser extent. Maximum activity was obtained at K+ concentrations above 20 millimolar. Potassium ions protected the enzyme against heat denaturation. The enzyme has a molecular weight of 68,300. Asparaginase acti...

A cDNA clone, designated as PvNAS2, encoding asparagine amidotransferase (asparagine synthetase) was isolated from nodule tissue of common bean (Phaseolus vulgaris cv. Negro Jamapa). Southern blot analysis indicated that asparagine synthetase in bean is encoded by a small gene family. Northern analysis of RNAs from various plant organs demonstrated that PvNAS2 is highly expressed in roots, foll...

In primary cultures of adult rat hepatocytes maintained in a salts/glucose medium, a more than 100-fold increase in ornithine decarboxylase (EC 4.1.1.17) activity was caused by asparagine and glucagon in a synergistic manner. The synthesis rate of ornithine decarboxylase was determined by [35S]methionine incorporation into the enzyme protein, and the amount of ornithine decarboxylase-mRNA was m...

The amino acid analog, albizziin, which acts as a competitive inhibitor of asparagine synthetase with respect to glutamine was used to isolate mutants of Chinese hamster ovary cells with alterations in levels of the target enzyme. These mutant lines have been characterized biochemically and genetically. Mutants selected in a single step are up to 40-fold more resistant to the drug than the pare...

With this system, no deamidation of glutamine occurred in the absence of a-keto acid, and, with all keto acids tested except two (pyruvate and a-ketobutyrate), transamination was absent or extremely slow when glutamate was substituted for glutamine. Experiments with W-labeled glutamine indicated that the ammonia evolved during this reaction was derived from t.he amide group of glutamine. Althou...